Cold Weather and Heart Attacks with Dr. Karol Watson
Cold temperatures cause arteries to tighten, restricting blood flow and reducing the oxygen supply to the heart, all of which can set the stage for a heart attack. In cold weather, there is more oxygen demand by the heart because it is working harder to do the work and maintain body heat.
Recent studies (Penn State) have shown that people with heart disease may not be able to compensate for their bodies' higher demand for oxygen when inhaling cold air, making snow shoveling and other activities dangerous for some. Breathing cold air during exercise can cause uneven oxygen distribution throughout the heart. But a healthy body generally corrects for this problem and redistributes blood flow, making sure the heart continues to function properly. In people with heart problems -- such as coronary artery disease -- this may not be the case. Studies show that in U.S., 54% more heart attacks in winter than summer. The winter heart attacks seem to be more serious, with a 9% fatality rate. Deaths due to heart attacks were highest on Dec. 25th, followed by Dec. 26th & Jan. 1st. Besides cold weather, other possible factors include changes in routines and environments, the rush of holiday events and the emotional impact of being with and without loved ones. And then there's the food (heavy holiday meals).
2) Which Activities Put People Most At Risk For Heart Problems In The Winter?Activities like snow shoveling, walking through heavy wet snow or in a snowdrift, downhill and cross country skiing, snow-boarding, can strain the heart enough to cause a heart attack. Snow shoveling is a real risk – it can be more strenuous than exercising full throttle on a treadmill. While this may not be a problem if an individual is healthy and fit, it can be dangerous if not. Shoveling, even pushing a heavy snow blower, can cause sudden increase in blood pressure and heart rate, and the cold air can cause constriction of the blood vessel and decrease oxygen to the heart. As you’re breathing cold air, your heart is doing more work – it’s consuming more oxygen. This can trigger a potentially fatal heart attack. Many people aren't conditioned to the physical stress of outdoor activities and don't know the dangers of being outdoors in cold weather. Besides cold temperatures, high winds, snow and rain also can steal body heat. Wind is especially dangerous, because it removes the layer of heated air from around your body. At 30 degrees Fahrenheit in a 30-mile wind, the cooling effect is equal to 15 degrees Fahrenheit. Similarly, dampness causes the body to lose heat faster than it would at the same temperature in drier conditions. This could lead to accidental hypothermia, which can also lead to fatal heart failure. Flu season is also peaking in the winter: the flu virus can cause inflammation that can also stress the heart.
2a) I Understand There’s Also A Danger For Heart Risk Due To Less Daylight Hours?
During the winter months, "there is a change in the ratio of daylight hours to dark hours, which changes the hormonal balance, and the hormones involved, such as cortisol, can lower the threshold for a cardiovascular event. 3) Who’s Most At Risk For Heart Attacks During Colder Weather?
Anyone with cardiovascular risk factors should beware. That includes the elderly, those that smoke, have high cholesterol, high blood pressure, are overweight -- or those with diabetes.
People with coronary heart disease often suffer angina pectoris (chest pain or discomfort) when they're in cold weather. Individuals who are at risk of a heart attack during cold outdoor activities include: those with a prior heart attack; those with known heart disease; those with high blood pressure or high cholesterol; smokers and those who lead a sedentary lifestyle.
4) What Can People Do To Reduce Their Risk Of Heart Attacks Before Shoveling Snow? – (or doing other strenuous outdoor activities?)
Talk to your doctor before you take on this task of snow shoveling.
Avoid shoveling immediately after you awaken as most heart attacks occur early in the morning when blood is more prone to clotting. Wait for at least 30 minutes and warm up. Do not eat heavy meal before shoveling: blood gets diverted form the heart to the stomach. Warm up your muscles before starting by walking for a few minutes or marching in place. Do not drink coffee or smoke for at least one hour before or one hour after shoveling or during breaks. These are stimulants and elevate your blood pressure and heart rate. And don't drink alcoholic beverages before going outdoors or when outside. Alcohol gives an initial feeling of warmth, because blood vessels in the skin expand. Heat is then drawn away from the body's vital organs.
4a) How Can People Reduce Their Heart Risks While Shoveling Snow?
Use a small shovel: shovel many small loads instead of heavy ones (or use a snow thrower).
Begin slowly and take frequent, 15 minute breaks. Drink plenty of water to avoid dehydration. Dress in layers, to avoid hypothermia (low body temperature) or overheating. Cover your head and neck (50% body heat lost thru head and neck). Cover your mouth (breathing cold air can cause angina or trigger breathing problems. Watch for warning signs of a heart attack: lightheadedness; dizziness; being short of breath or if you have tightness or burning in chest, neck, arms or back. If you think you are having a heart attack call 911.
Learn CPR. Effective bystander CPR, provided immediately after sudden cardiac arrest, can double or triple a victim’s chance of survival. Hands-only CPR makes it easier than ever to save a life. If an adult suddenly collapses, call 9-1-1 and begin pushing hard and fast in the middle of the victim’s chest until help arrives.